Autism, more correctly termed autistic spectrum disorder (ASD), is defined by NICE as: ‘A persistent disorder, present from early childhood, which significantly limits or impairs activities of daily living… characterised by developmental impairments in social interaction and social communication.’1
Autism can present in a variety of ways, including difficulties in conversation, non-verbal communication and the development and maintenance of relationships. There may also be restricted and repetitive behaviours such as idiosyncratic motor movements and fixed interests, as well as difficulty in coping with changes to routines. As implied by the name, ASD is a spectrum, with symptoms varying widely in severity.
The estimated prevalence of ASD in children is around 1%,1 with around three to four times more boys affected than girls, leading to the perception that girls rarely have ASD. However, concerns have been raised that this is due to under-diagnosis in girls,1,2 who may present in less obvious ways. A delayed diagnosis can have a significant impact on quality of life and achievements in education and the workplace, so it is important for healthcare professionals not to dismiss the possibility in girls.
Why might ASD be missed in girls?
There is no ‘one size fits all’ approach to improving diagnostic rates of ASD in girls, but a good start is to understand the potential reasons for delayed diagnosis.
Much of the early research on childhood ASD looked at groups of patients in which there were many more boys than girls and therefore the diagnostic criteria have generally been written with male patients in mind.
In recent years, attention has started to focus on the so-called ‘female autism phenotype’,3 which describes the different ways in which girls with ASD present to boys, and the concept that girls may be better able to camouflage their difficulties, by actions such as imitating others and using their intellect to fit in with their peers, even if it means consciously masking their autistic behaviours.
Superficially, they may therefore seem to have fewer social difficulties but they may struggle with the more subtle aspects of socialising and find it difficult to maintain long-term friendships and relationships.3
Girls may develop intense fixed interests that are considered gender appropriate and so not seen as out of the ordinary. Also, while boys with ASD who externalise their problems, presenting with aggression, inattention or behavioural issues, are likely to come to the attention of the authorities at an early stage, girls who internalise these difficulties may be diagnosed (possibly wrongly) with anxiety, depression, personality disorders or eating disorders, while the underlying ASD is missed.
Camouflaging, or masking of difficulties, in girls with ASD has been suggested in research papers from as early as 1981, and more recently women diagnosed with ASD have chronicled struggles to fit in after years of ‘pretending to be normal’.4,5 Qualitative evidence shows that girls may be more likely to mimic their peers, which may conceal the characteristics of ASD.6 This may be done consciously in an attempt to make friends and can be exhausting. This has led to the concept of the ‘coke bottle effect’,7 whereby efforts to mask ASD traits are likened to the shaking of a fizzy drink: the child manages to hold things together while at school, but when they get home into an environment that seems safer, all the stresses of the day erupt as if the cap has suddenly been removed from the bottle.
How can nurses pick up on potential ASD?
We can’t make a diagnosis if we don’t think of it as a possibility. Women diagnosed with ASD in late adolescence or later report a variety of issues in their early years.8 These included healthcare professionals not considering ASD, and dismissing it if raised by the person herself. Many also felt stereotypes about ASD presentation hindered their diagnosis; one was told by a special needs teacher that she wasn’t good enough at maths to be autistic.
There was also a feeling that having meltdowns at home rather than at school, and being considered a ‘model pupil’ meant concerns were not taken seriously at a primary age. In secondary school as problems developed, girls were told that they were rude or lazy if they didn’t understand social cues. The research also found a high level of sexual abuse in the study group. Potential reasons explored included isolation from peers who might have helped to keep them safe, and a feeling of being obliged to have sex when they didn’t want to. Larger studies have confirmed that symptoms of neurodevelopmental disorders and ASD are a vulnerability factor for sexual abuse.9,10
So how can our knowledge of these issues translate into earlier diagnosis and a better outcome for girls with ASD? Mental health services are swamped at the moment, but in primary care if we can consider the diagnosis, take concerns seriously and make a timely referral then we will be doing our best to help girls and women under our care to achieve their full potential.
Dr Toni Hazell is a GP in north London
- NICE CKS. Autism in children. London: NICE, 2020. Link
- NICE. Autism spectrum disorder in under 19s: recognition, referral and diagnosis. London: NICE, 2017. Link
- Hull L et al. The female autism phenotype and camouflaging: a narrative review. Rev J Autism Dev Disord 2020;7:306-17. Link
- Holliday Willey L. Pretending to be normal: Living with Asperger’s syndrome (Expanded edition). London: Jessica Kingsley, 2015.
- Mumford M. Temple Grandin, autism acceptance and why it’s awesome to be autistic in STEM. 8 April 2021. Link
- Rynkiewicz A et al. An investigation of the ‘female camouflage effect’ in autism using a computerized ADOS-2 and a test of sex/gender differences. Mol Autism 2016;7:10. Link
- Fisher S. The coke bottle effect. 2021. Link
- Bargiela S et al.The experiences of late-diagnosed women with autism spectrum conditions: An investigation of the female autism phenotype. J Autism Dev Disord 2016;46:3281-94. Link
- Choudhury N. Nine out of ten autistic women are victims of sexual assault. Open Access Government. 28 April 2022 Link
- Ohlsson Gotby V et al. Childhood neurodevelopmental disorders and risk of coercive sexual victimization in childhood and adolescence – a population-based prospective twin study. J Child Psychol Psychiatry 2018;59(9):957-65. Link